hi dear
I am not a regular REGCMer, but can answer this one. The model is hydrostatic and therefore resolutions of 1km are not possible. Usually the limit for a hydrostatic model is about 7 to 8 km. I understand some people have used REGCM with 10km in the past. Plans are afoot to create a non-hydrostatic version of REGCM but this will take a while.
best,
Fattahi |